Fluorinated olefins having a carbon--carbon double bond, the carbon atoms of which have a fluorine atom, are used as intermediate materials for fluorinated paraffins used as chlorofluorocarbon alternatives, and monomers for fluorinated polymers, and are produced in a large scale.
Heretofore, these fluorinated olefins have been produced by reacting an olefin compound having a carbon--carbon double bond, the carbon atoms of which have a chlorine atom, with an alkali metal fluoride. For example, 1,2,3,3,4,4,5,5-octafluorocyclopentene is produced by reacting 1,2-dichloro-3,3,4,4,5,5-hexafluorocyclopentene with potassium fluoride [U.S. Pat. No. 3,024,290, ibid. U.S. Pat. No. 3,567,788, and J. Org. Chem., 28, 112(1963)]. However, the yield of the intended product is insufficient for the production thereof in a commercial scale, and thus, enhancement of the yield is desired.